How to reverse the colormap of an image to scalar values in Matplotib?

To reverse the colormap of an image, we can take the following steps −

Set the figure size and adjust the padding between and around the subplots.
Create random data points using x and y.
Get the blue color map using get_cmap() method.
Add a subplot to the current figure at index 1.
Plot x and y data points using scatter() method.
Create a colorbar for a scalar mappable instance.
Plot x and y data points using scatter() method, with reversed colormap.
Set the title of both the axes.
To display the figure, use show() method.

Example

import matplotlib.pyplot as plt
import numpy as np

plt.rcParams["figure.figsize"] = [7.50, 3.50]
plt.rcParams["figure.autolayout"] = True

x = np.linspace(-2, 2, 10)
y = np.linspace(-2, 2, 10)

color_map = plt.cm.get_cmap('Blues')
plt.subplot(1, 2, 1)

sc = plt.scatter(x, y, c=x, cmap=color_map)
plt.colorbar(sc)

plt.title("Colorbar")
plt.subplot(1, 2, 2)
sc = plt.scatter(x, y, c=x, cmap=color_map.reversed())
plt.colorbar(sc)

plt.title("Reversed Colorbar")

plt.show()

Output

Rishikesh Kumar Rishi

Updated on: 2021-06-10T12:02:31+05:30

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